Abstract: A suction cup device includes a cup forming unit cooperating with a flat surface to create a volume-variable space, a liftable rod secured to a central portion of the cup forming unit, a bracing shell member having a force-transmitting surrounding wall in engagement with a peripheral portion of the cup forming unit, and a twistable cap member having a surrounding bottom wall in abutting against a circumferential abutment region of the bracing shell member and threadedly engaged with the liftable rod such that a manually twisted movement of the twistable cap member can result in axial movement of the rod so as to pull the central portion away from the flat surface to produce a reduced pressure in the volume-variable space and a biasing force to thereby ensuring fluid-tight engagement of the cup forming unit with the flat surface.

Abstract: A suction cup device includes a cup forming unit cooperating with a flat surface to create a volume-variable space, a liftable rod secured to a central portion of the cup forming unit, a bracing shell member having a force-transmitting surrounding wall in engagement with a peripheral portion of the cup forming unit, and a twistable cap member having a surrounding bottom wall in abutting against a circumferential abutment region of the bracing shell member and threadedly engaged with the liftable rod such that a manually twisted movement of the twistable cap member can result in axial movement of the rod so as to pull the central portion away from the flat surface to produce a reduced pressure in the volume-variable space and a biasing force to thereby ensuring fluid-tight engagement of the cup forming unit with the flat surface.